Set the Instant Pot to Sauté and cook the Italian sausage with the diced yellow onion and minced garlic until browned, stirring occasionally, about 5 minutes. Visual cue: the sausage should lose its pink color and the onion should look softened.

Add the crushed tomatoes, chicken broth, and Italian seasoning, then place the broken lasagna noodles on top without stirring. Visual cue: the noodles should sit as a layer above the liquid (no mixing into the broth).

Seal the lid and pressure cook on high for 5 minutes. Visual cue: the Instant Pot display should read the full pressure-cook time before the countdown ends.

Use a quick release to stop the cooking. Visual cue: the floating valve drops and the steam vents shortly after.

Stir in the heavy cream until the broth looks silky and evenly tinted. Visual cue: you should see a smooth, lighter-red consistency with no cream streaks.

Top the soup with ricotta and grated Parmesan. Visual cue: the cheeses should sit on top and begin to soften from the hot soup rather than fully disappear.